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KINGDOM ANIMALIA

Kingdom animalia is divided into two sub kingdoms- Parazoa (cellular level) and Eumetazoa (tissue level) Subkingdom Parazoa includes the Phylum Porifera. Subkingdom Eumetazoa includes all the Phyla from coelenterates to chordates.

Phylum Porifera

Features of porifera:1. Sessile, sedentary and marine.2. Body is perforated by numerous pores, called Ostia.3. One large opening called osculum. 4. Shows cellular level of organisation. 5. Shows presence of canal system. 6. No mouth, no anus. 7. Has choanocytes in the radial canals. 8. Inner part is hollow or permeated by canals, cavity is called spongocoel. 9. Body has skeleton made up of spongin or spicules. 10. Reproduction is by budding and fragmentation.Eg. Leucosolenia, Euplectella, Euspongia.

METAGENESIS

Metagenesis is the type of life cycle in which there are two different forms of individuals of the same species, one haploid and the other diploid. In one of these stages gametogenesis occurs and fecundated gametes give birth to the zygote that then develops into the other form. (Obelia)Metagenesis is also known as alternation of generations or as diplobiont life cycle.

EXAMPLES OF CTENOPHORA

PLEUROBRANCHIA

BEROE

Phylum Platyhelminthes

Features of Platyhelminthes:1.Bilaterally symmetrical and dorsoventrally flattened, triploblastic and acoelomate.2. Body shape worm like but varies from flat ribbon like to leaf like. 3. Anterior end differentiated to form head which bears hooks and suckers. 4. Skeleton absent. 5. Acoelomate with protonephridia or flame cells for excretion. 6. Hermaphrodite shows both sexual and asexual method of reproduction. 7. Free living or parasites. Eg. Planaria, Liver fluke, Taenia (Tape worm)

ADAPTATIONS FOR PARASITIC LIFE

Resistant horny cuticle, no epidermis

Adhesive structures present.

Locomotory, circulatory and respiratory system absent.

Alimentary canal, incomplete or absent.

Sense organs absent or poorly developed.

Highly developed reproductive organs.

EXAMPLES OF PLATYHELMINTHES

PLANARIA

LIVERFLUKE

TAPEWORM

Phylum Aschelminthes

Features of Aschelminthes:

Bilaterally symmetrical, unsegmented worms.

Triploblastic, microscopic with cylindrical or flattened body.

Alimentary canal straight with mouth and anus.

Excretory system with protonephridia for osmoregulation.

Nervous system simple with some sense organs like bristles and eye spots.

Sexes separate females longer than the males.

Eg Ascaris, Wuchereria bancrofti

ASCARIS

WUCHERERIA

Phylum Annelida

Features of Annelida:

Mainly aquatic, marine or fresh water, burrowing or living in tubes, some free living forms.

Triploblastic, bilateral, elongated and vermiform.

Metamerically segmented body covered with cuticle.

Locomotary organs are setae or parapodia parasitic forms do not have either.

True coelom present, respiration through body surface.

Closed blood vascular system, haemoglobin present.

Nervous system consists of brain and segmental ganglia.

Excretion by nephridia.

Sexes separate in polychaetes, earthworms and leeches are hermaphrodite.

Eg. Nereis Earthworm. Leeches

METAMERIC SEGEMENTATION

Linear series of body segmentation fundamentally similar in structure. Each metameric segment is referred to as metamere or somite. Earthworms show heteronomous metamery where the metameres are grouped to perform similar tasks.Nereis shows homonomous metamery where the metameres are in serial succession.

LOCOMOTORY ORGANS IN ANNELIDA

Setae or chaetae: These are tiny bristle like structures present on the segments of animals of Oligochaetes (class of Annelid). The setae are present on all the segments except the first and the last. These structures help the earthworm to move.

Parapodia: These are fleshy lobes present on each segment in Polychaets (class of Annelid). Parapodia are paired, lateral appendages extending from the body segements. A parapodium is basically biramous or uniramous, having one branch or two branches.

EXAMPLES OF ARTHROPODA

SPIDER

SCORPION

CENTIPEDE

DIFFERENCE BETWEEN BUTTERFLY AND MOTH

BUTTERFLY1. Butterflies are brightly coloured.2. They are diurnal (Active during day).3. The wings are arranged vertically at rest.4. Antennae are long, filamentous and clubbed.5. Body slender and scaly.

MOTH1. Moths are dull coloured.2. They are nocturnal (active during night).3. The wings at rest are arranged horizontally.4. Antennae are short and feathery.5. Body is broad and stout.

Find out and list the differences between anopheles and culex mosquitoes

Phylum Mollusca

Features of Mollusca:

Aquatic, marine, few terrestrial and fresh water forms.

Body soft, unsegmented, triploblastic, bilaterally symmetrical.

Body consists of head, foot, mantle and visceral mass.

Commonly protected by exoskeleton made of one or more calcareous pieces.

Body cavity called haemocoel, with open circulatory system.

Respiratory system with gills and pigment is haemocyanin.

Excretory system consisting of metanephridia and nervous system well developed.

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